The partner of Guardian journalist Glenn Greenwald has reportedly begun legal action to prevent the British government from investigating material taken from him during his detention at London’s Heathrow Airport.

The lawyers for David Miranda, who is the partner of the journalist working with NSA leaker Edward Snowden, told Reuters they are seeking judicial review of Miranda’s detention, and thus asking authorities to not inspect anything taken from Miranda until that is complete.

If authorities don’t respond, the lawyers told Reuters, they would take the matter to the country’s high court.

Miranda was on his way from a meeting in Berlin with filmmaker Laura Poitras to the home in Brazil he shares with Greenwald when he was detained Sunday for nine hours under Britain’s Terrorism Act. Before he was released, authorities confiscated electronics including his mobile devices, memory sticks, laptop, camera and video game consoles, according to Greenwald.